scholarly journals Structure supports function: informing directed and dynamic functional connectivity with anatomical priors

2021 ◽  
pp. 1-37
Author(s):  
David Pascucci ◽  
Maria Rubega ◽  
Joan Rué-Queralt ◽  
Sebastien Tourbier ◽  
Patric Hagmann ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Diffusion Tensor ◽  
Signal To Noise Ratio ◽  
Meta Analysis ◽  
Structural Connectivity ◽  
Eeg Data ◽  
Functional Brain Networks ◽  
And Function ◽  
Combine Information ◽  
Anatomical Priors

Abstract The dynamic repertoire of functional brain networks is constrained by the underlying topology of structural connections. Despite this intrinsic relationship between structural (SC) and functional connectivity (FC), integrative and multimodal approaches to combine the two remain limited. Here, we propose a new adaptive filter for estimating dynamic and directed FC using structural connectivity information as priors. We tested the filter in rat epicranial recordings and human event-related EEG data, using SC priors from a meta-analysis of tracer studies and diffusion tensor imaging metrics, respectively. We show that, particularly under conditions of low signal-to-noise ratio, SC priors can help to refine estimates of directed FC, promoting sparse functional networks that combine information from structure and function. In addition, the proposed filter provides intrinsic protection against SC-related false negatives, as well as robustness against false positives, representing a valuable new tool for multimodal imaging in the context of dynamic and directed FC analysis.

scholarly journals Structure supports function: informing directed and dynamic functional connectivity with anatomical priors

2021 ◽  
Author(s):  
David Pascucci ◽  
Maria Rubega ◽  
Joan Rue-Queralt ◽  
Sebastien Tourbier ◽  
Patric Hagmann ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Diffusion Tensor ◽  
Meta Analysis ◽  
Structural Connectivity ◽  
Brain Regions ◽  
Noise Perturbation ◽  
Eeg Data ◽  
Functional Brain Networks ◽  
Anatomical Priors ◽  
And Diffusion

The dynamic repertoire of functional brain networks is constrained by the underlying topology of structural connections: the lack of a direct structural link between two brain regions prevents direct functional interactions. Despite the intrinsic relationship between structural (SC) and functional connectivity (FC), integrative and multimodal approaches to combine the two remain limited, especially for electrophysiological data. In the present work, we propose a new linear adaptive filter for estimating dynamic and directed FC using structural connectivity information as priors. We tested the filter in rat epicranial recordings and human event-related EEG data, using SC priors from a meta-analysis of tracer studies and diffusion tensor imaging metrics, respectively. Our results show that SC priors increase the resilience of FC estimates to noise perturbation while promoting sparser networks under biologically plausible constraints. The proposed filter provides intrinsic protection against SC-related false negatives, as well as robustness against false positives, representing a valuable new method for multimodal imaging and dynamic FC analysis.

scholarly journals Age-dependent differences in functional brain networks are atypical in Tourette syndrome

2020 ◽  
Author(s):  
Ashley N. Nielsen ◽  
Caterina Gratton ◽  
Soyoung Kim ◽  
Jessica A. Church ◽  
Kevin J. Black ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Tourette Syndrome ◽  
Time Course ◽  
Neurodevelopmental Disorder ◽  
Developmental Differences ◽  
Functional Networks ◽  
Functional Neuroanatomy ◽  
Brain Structure And Function ◽  
Functional Brain Networks ◽  
And Function

AbstractTourette syndrome (TS) is a neurodevelopmental disorder characterized by motor and vocal tics. TS is complex, with symptoms that involve sensory, motor, and top-down control processes and that fluctuate over the course of development. While many have studied atypical brain structure and function associated with TS, the neural substrates supporting the complex range and time-course of symptoms is largely understudied. Here, we used functional connectivity MRI to examine functional networks across the whole-brain in children and adults with TS. To investigate the functional neuroanatomy of childhood and adulthood TS, we separately considered the sets of connections within each functional network and those between each pair of functional networks. We tested whether developmental stage (child, adult), diagnosis (TS, control), or an interaction between these factors was present among these connections. We found that developmental changes for most functional networks in TS were unaltered (i.e., developmental differences in TS were similar to those in typically developing children and adults). However, there were several within-network and cross-network connections that exhibited either “divergent” or “attenuated” development in TS. Connections involving the somatomotor, cingulo-opercular, auditory, dorsal attention, and default mode networks diverged from typical development in TS, demonstrating enhanced functional connectivity in adulthood TS. In contrast, connections involving the basal ganglia, thalamus, cerebellum, auditory, visual, reward, and ventral attention networks showed attenuated developmental differences in TS. These results suggest that adulthood TS is characterized by increased functional connectivity among functional networks that support cognitive control and attention, which may be implicated in suppressing, producing, and attending to tics. In contrast, subcortical systems that have been implicated in the initiation and production of tics may be immature in adulthood TS. Jointly, our results reveal how several cortical and subcortical functional networks interact and differ across development in TS.

scholarly journals Structural and Functional Connectivity Substrates of Cognitive Impairment in Multiple Sclerosis

2021 ◽  
Vol 12 ◽  
Author(s):  
Jian Zhang ◽  
Rosa Cortese ◽  
Nicola De Stefano ◽  
Antonio Giorgio
Keyword(s):  
Multiple Sclerosis ◽  
Cognitive Impairment ◽  
Functional Connectivity ◽  
Diffusion Tensor ◽  
Structural Connectivity ◽  
Diffusion Kurtosis Imaging ◽  
High Angular Resolution ◽  
Diffusion Spectrum Imaging ◽  
Analysis Methods ◽  
Scan Time

Cognitive impairment (CI) occurs in 43 to 70% of multiple sclerosis (MS) patients at both early and later disease stages. Cognitive domains typically involved in MS include attention, information processing speed, memory, and executive control. The growing use of advanced magnetic resonance imaging (MRI) techniques is furthering our understanding on the altered structural connectivity (SC) and functional connectivity (FC) substrates of CI in MS. Regarding SC, different diffusion tensor imaging (DTI) measures (e.g., fractional anisotropy, diffusivities) along tractography-derived white matter (WM) tracts showed relevance toward CI. Novel diffusion MRI techniques, including diffusion kurtosis imaging, diffusion spectrum imaging, high angular resolution diffusion imaging, and neurite orientation dispersion and density imaging, showed more pathological specificity compared to the traditional DTI but require longer scan time and mathematical complexities for their interpretation. As for FC, task-based functional MRI (fMRI) has been traditionally used in MS to brain mapping the neural activity during various cognitive tasks. Analysis methods of resting fMRI (seed-based, independent component analysis, graph analysis) have been applied to uncover the functional substrates of CI in MS by revealing adaptive or maladaptive mechanisms of functional reorganization. The relevance for CI in MS of SC–FC relationships, reflecting common pathogenic mechanisms in WM and gray matter, has been recently explored by novel MRI analysis methods. This review summarizes recent advances on MRI techniques of SC and FC and their potential to provide a deeper understanding of the pathological substrates of CI in MS.

scholarly journals Two classes of functional connectivity in dynamical processes in networks

2021 ◽  
Vol 18 (183) ◽  
Author(s):  
Venetia Voutsa ◽  
Demian Battaglia ◽  
Louise J. Bracken ◽  
Andrea Brovelli ◽  
Julia Costescu ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Network Architecture ◽  
Structural Connectivity ◽  
Ecological Systems ◽  
Dynamical Processes ◽  
Structure And Dynamics ◽  
Theoretical View ◽  
And Function ◽  
The Relationship ◽  
Simultaneous Activity

The relationship between network structure and dynamics is one of the most extensively investigated problems in the theory of complex systems of recent years. Understanding this relationship is of relevance to a range of disciplines—from neuroscience to geomorphology. A major strategy of investigating this relationship is the quantitative comparison of a representation of network architecture (structural connectivity, SC) with a (network) representation of the dynamics (functional connectivity, FC). Here, we show that one can distinguish two classes of functional connectivity—one based on simultaneous activity (co-activity) of nodes, the other based on sequential activity of nodes. We delineate these two classes in different categories of dynamical processes—excitations, regular and chaotic oscillators—and provide examples for SC/FC correlations of both classes in each of these models. We expand the theoretical view of the SC/FC relationships, with conceptual instances of the SC and the two classes of FC for various application scenarios in geomorphology, ecology, systems biology, neuroscience and socio-ecological systems. Seeing the organisation of dynamical processes in a network either as governed by co-activity or by sequential activity allows us to bring some order in the myriad of observations relating structure and function of complex networks.

Loneliness in late-life depression: structural and functional connectivity during affective processing

2016 ◽  
Vol 46 (12) ◽  
pp. 2485-2499 ◽  
Author(s):  
N. M. L. Wong ◽  
H.-L. Liu ◽  
C. Lin ◽  
C.-M. Huang ◽  
Y.-Y. Wai ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Emotion Dysregulation ◽  
Diffusion Tensor ◽  
Structural Connectivity ◽  
Late Life ◽  
The Elderly ◽  
Affective Processing ◽  
Late Life Depression ◽  
Processing Task ◽  
Affective Stimuli

BackgroundLate-life depression (LLD) in the elderly was reported to present with emotion dysregulation accompanied by high perceived loneliness. Previous research has suggested that LLD is a disorder of connectivity and is associated with aberrant network properties. On the other hand, perceived loneliness is found to adversely affect the brain, but little is known about its neurobiological basis in LLD. The current study investigated the relationships between the structural connectivity, functional connectivity during affective processing, and perceived loneliness in LLD.MethodThe current study included 54 participants aged >60 years of whom 31 were diagnosed with LLD. Diffusion tensor imaging (DTI) data and task-based functional magnetic resonance imaging (fMRI) data of an affective processing task were collected. Network-based statistics and graph theory techniques were applied, and the participants’ perceived loneliness and depression level were measured. The affective processing task included viewing affective stimuli.ResultsStructurally, a loneliness-related sub-network was identified across all subjects. Functionally, perceived loneliness was related to connectivity differently in LLD than that in controls when they were processing negative stimuli, with aberrant networking in subcortical area.ConclusionsPerceived loneliness was identified to have a unique role in relation to the negative affective processing in LLD at the functional brain connectional and network levels. The findings increas our understanding of LLD and provide initial evidence of the neurobiological mechanisms of loneliness in LLD. Loneliness might be a potential intervention target in depressive patients.

scholarly journals Neonatal Functional and Structural Connectivity Are Associated with Cerebral Palsy at Two Years of Age

2019 ◽  
Vol 37 (02) ◽  
pp. 137-145
Author(s):  
Stephanie L. Merhar ◽  
Elveda Gozdas ◽  
Jean A. Tkach ◽  
Nehal A. Parikh ◽  
Beth M. Kline-Fath ◽  
...  
Keyword(s):  
Cerebral Palsy ◽  
Brain Injury ◽  
Functional Connectivity ◽  
Diffusion Tensor ◽  
Structural Connectivity ◽  
Motor Task ◽  
Structural Mri ◽  
Perinatal Brain Injury ◽  
The Right ◽  
Almost All

Objective The accuracy of structural magnetic resonance imaging (MRI) to predict later cerebral palsy (CP) in newborns with perinatal brain injury is variable. Diffusion tensor imaging (DTI) and task-based functional MRI (fMRI) show promise as predictive tools. We hypothesized that infants who later developed CP would have reduced structural and functional connectivity as compared with those without CP. Study Design We performed DTI and fMRI using a passive motor task at 40 to 48 weeks' postmenstrual age in 12 infants with perinatal brain injury. CP was diagnosed at age 2 using a standardized examination. Results Five infants had CP at 2 years of age, and seven did not have CP. Tract-based spatial statistics showed a widespread reduction of fractional anisotropy (FA) in almost all white matter tracts in the CP group. Using the median FA value in the corticospinal tracts as a cutoff, FA was 100% sensitive and 86% specific to predict CP compared with a sensitivity of 60 to 80% and a specificity of 71% for structural MRI. During fMRI, the CP group had reduced functional connectivity from the right supplemental motor area as compared with the non-CP group. Conclusion DTI and fMRI obtained soon after birth are potential biomarkers to predict CP in newborns with perinatal brain injury.

scholarly journals T163. STRUCTURAL AND CONNECTIVITY CHANGES IN THE CEREBELLUM CONTRIBUTE TO EXPERIENCING AUDITORY VERBAL HALLUCINATIONS

2020 ◽  
Vol 46 (Supplement_1) ◽  
pp. S293-S293
Author(s):  
Ana Pinheiro ◽  
Sylvain Bouix ◽  
Nikos Makris ◽  
Michael Schwartze ◽  
Martha Shenton ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Diffusion Tensor ◽  
Meta Analysis ◽  
Structural Mri ◽  
Small Sample ◽  
Forward Model ◽  
Resting State Functional Connectivity ◽  
Auditory Verbal Hallucinations ◽  
Crus I ◽  
The Right

Abstract Background Auditory verbal hallucinations (AVH) have been explained in the context of the forward model, giving the cerebellum a prominent role. However, research utilizing multiple neuroimaging modalities has rendered results on the specificity of cerebellar contribution to AVH unclear. Methods To examine the reliability and regional specificity of cerebellar changes in AVH, a systematic search of electronic databases through October 2019 was conducted to identify neuroimaging studies of the cerebellum in psychotic patients or nonclinical participants reporting AVH, focusing on structural MRI, diffusion tensor imaging, and resting state functional connectivity studies. Twenty-two studies were selected, including 892 participants with AVH (792 psychotic patients; 100 at-risk subjects) and 775 healthy controls. Activation likelihood estimate analysis (ALE) examined the reported coordinates for reduced volume, fractional anisotropy (FA) or connectivity (control participants > participants with AVH) and increased volume, FA or connectivity (participants with AVH > control participants). The consistency of cerebellar changes and their relationship with sociodemographic and clinical measures were meta-analyzed. Results The ALE meta-analysis revealed changes in both anterior and posterior cerebellar lobes, with opposite patterns: whereas decreased volume or connectivity was identified in the right anterior cerebellum (lobule IV/V), increased volume or connectivity was identified in the bilateral posterior cerebellum (Crus I and II). A random-effects model with small sample corrections identified consistent changes in both volume and functional connectivity of the cerebellum in participants with AVH (g = .84; SE = .24, 95% CI [.33, 1.34]), which were enhanced in Crus I (g = 1.52, SE = .28, p = .006, 95% CI [.73, 2.31]) but not moderated by age, sex, medication, or illness duration. Discussion The ALE meta-analysis confirms cerebellar structural and connectivity changes in psychotic and nonclinical participants reporting AVH. These changes may contribute to AVH due to altered sensory feedback and consequently to erratic prediction as described by the forward model. The current findings also indicate that not all cerebellar regions are equally affected by AVH: the most pronounced changes were observed in Crus I. Specifically, altered communication between Crus I and neocortical network nodes, including the prefrontal cortex, may contribute to ineffective cognitive control in AVH, leading to external misattributions of auditory feedback and a reduced sense of control over events in the environment.

scholarly journals Relationships between Diffusion Tensor Imaging and Resting State Functional Connectivity in Patients with Schizophrenia and Healthy Controls: A Preliminary Study

2022 ◽  
Author(s):  
Matthew J. Hoptman ◽  
Umit Tural ◽  
Kelvin O. Lim ◽  
Daniel C. Javitt ◽  
Lauren E. Oberlin
Keyword(s):  
Diffusion Tensor Imaging ◽  
Functional Connectivity ◽  
Resting State ◽  
Diffusion Tensor ◽  
Structural Connectivity ◽  
Resting State Fmri ◽  
Resting State Functional Connectivity ◽  
Syndrome Scale ◽  
Healthy Control ◽  
Negative Syndrome

Schizophrenia is widely seen as a disorder of dysconnectivity. Neuroimaging studies have examined both structural and functional connectivity in the disorder, but these modalities have rarely been integrated directly. We scanned 29 patients with schizophrenia and 25 healthy control subjects and acquired resting state fMRI and diffusion tensor imaging. The Functional and Tractographic Connectivity Analysis Toolbox (FATCAT) was used to estimate functional and structural connectivity of the default mode network. Correlations between modalities were investigated, and multimodal connectivity scores (MCS) were created using principal components analysis. Nine of 28 possible region pairs showed consistent (>80%) tracts across participants. Correlations between modalities were found among those with schizophrenia for the prefrontal cortex, posterior cingulate, and lateral temporal lobes with frontal and parietal regions, consistent with frontotemporoparietal network involvement in the disorder. In patients, MCS values correlated with several aspects of the Positive and Negative Syndrome Scale, positively with those involving inwardly directed psychopathology, and negatively with those involving external psychopathology. In this preliminary sample, we found FATCAT to be a useful toolbox to directly integrate and examine connectivity between imaging modalities. A consideration of conjoint structural and functional connectivity can provide important information about the network mechanisms of schizophrenia.

scholarly journals Relationships between Diffusion Tensor Imaging and Resting State Functional Connectivity in Patients with Schizophrenia and Healthy Controls: A Preliminary Study

2021 ◽  
Author(s):  
Matthew J. Hoptman ◽  
Umit Tural ◽  
Kelvin O. Lim ◽  
Daniel C. Javitt ◽  
Lauren E. Oberlin
Keyword(s):  
Diffusion Tensor Imaging ◽  
Functional Connectivity ◽  
Resting State ◽  
Diffusion Tensor ◽  
Structural Connectivity ◽  
Resting State Fmri ◽  
Resting State Functional Connectivity ◽  
Syndrome Scale ◽  
Healthy Control ◽  
Negative Syndrome

Schizophrenia is widely seen as a disorder of dysconnectivity. Neuroimaging studies have examined both structural and functional connectivity in the disorder, but these modalities have rarely been integrated directly. We scanned 29 patients with schizophrenia and 25 healthy control subjects and acquired resting state fMRI and diffusion tensor imaging. The Functional and Tractographic Connectivity Analysis Toolbox (FATCAT) was used to estimate functional and structural connectivity of the default mode network. Correlations between modalities were investigated, and multimodal connectivity scores (MCS) were created using principal components analysis. Nine of 28 possible region pairs showed consistent (>80%) tracts across participants. Correlations between modalities were found among those with schizophrenia for the prefrontal cortex, posterior cingulate, and lateral temporal lobes with frontal and parietal regions, consistent with frontotemporoparietal network involvement in the disorder. In patients, MCS values correlated with several aspects of the Positive and Negative Syndrome Scale, positively with those involving inwardly directed psychopathology, and negatively with those involving external psychopathology. In this preliminary sample, we found FATCAT to be a useful toolbox to directly integrate and examine connectivity between imaging modalities. A consideration of conjoint structural and functional connectivity can provide important information about the network mechanisms of schizophrenia.

scholarly journals Altered White Matter Microstructural Organization in Post-Traumatic Stress Disorder across 3,049 Adults: Results from the PGC-ENIGMA PTSD Consortium

2019 ◽  
Author(s):  
Emily L Dennis ◽  
Seth G Disner ◽  
Negar Fani ◽  
Lauren E Salminen ◽  
Mark Logue ◽  
...  
Keyword(s):  
White Matter ◽  
Stress Disorder ◽  
Meta Analysis ◽  
Cohort Analysis ◽  
Structural Connectivity ◽  
Small Sample ◽  
Post Traumatic Stress ◽  
History Of ◽  
Small Sample Sizes ◽  
And Function

AbstractA growing number of studies have examined alterations in white matter organization in people with posttraumatic stress disorder (PTSD) using diffusion MRI (dMRI), but the results have been mixed, which may be partially due to relatively small sample sizes among studies. Altered structural connectivity may be both a neurobiological vulnerability for, and a result of, PTSD. In an effort to find reliable effects, we present a multi-cohort analysis of dMRI metrics across 3,049 individuals from 28 cohorts currently participating in the PGC-ENIGMA PTSD working group (a joint partnership between the Psychiatric Genomics Consortium and the Enhancing NeuroImaging Genetics through Meta-Analysis consortium). Comparing regional white matter metrics across the full brain in 1,446 individuals with PTSD and 1,603 controls (2152 males/897 females) between ages 18-83, 92% of whom were trauma-exposed, we report associations between PTSD and disrupted white matter organization measured by lower fractional anisotropy (FA) in the tapetum region of the corpus callosum (Cohen’sd=−0.12,p=0.0021). The tapetum connects the left and right hippocampus, structures for which structure and function have been consistently implicated in PTSD. Results remained significant/similar after accounting for the effects of multiple potentially confounding variables: childhood trauma exposure, comorbid depression, history of traumatic brain injury, current alcohol abuse or dependence, and current use of psychotropic medications. Our results show that PTSD may be associated with alterations in the broader hippocampal network.

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